Precision oil feed tap



March 21, 1961 M. FALCO 2,975,441

PRECISION OIL FEED TAP Filed Nov. 25, 1957 2 Sheets-Sheet 1 Michele Fa/co IN VE N TOR.

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March 21, 1961 M. FALCO PRECISION OIL FEED TAP 2 Sheets-Sheet 2 Filed NOV. 25, 1957 Fig.3

Michele Fa/co INVENTOR.

9 BY WW 19m v United States Patent '0 PRECISION on. FEED TAP Michele Falco, 296 Liberty St., Paine'sville, ohm

Filed Nov. 25, 1957, Ser. No. 698,432

1 Claim. c1. 10-141 This invention relates to a tap and more particularly to a precision tap that has internal oil feeding.

An object of the invention is -to provide a fully lubricated tap by having oil fed under pressure to points of emission where the oil is most needed. The tap which exemplifies my invention is superior to presently used taps in that the work is correctly lubricated at the actual points of contact between the work and the tap, the chips are flowed free of the tap, the tap remains cooler because of the inherent cooling function of the flowing lubricating oil, and lasts longer.

A more specific object of the invention is to provide a lubricated precision tap enabling a machinist or instrument maker to do better work. Cutting oil is conducted under pressure through a number of internal passageways that discharge in and around the area that is being threaded. The oil is collected for recirculation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a fragmentary elevational view showing my tap and oil feed assembly;

Figure 2 is a perspective view of the tap in Figure 1;

Figure 3 is a sectional view taken on the line 3-3 of Figure 2;

Figure 4 is an end view of the tap in Figure 3;

Figure 5 is a cross sectional view taken on the line 55 of Figure 3;

Figure 6 is an elevational view of a fluted tap constructed in accordance with the invention; and

' Figure 7 is an end view of the tap in Figure 6 with the internal network of passages and passageways of Figure 6 being the same as the tap of Figure 3.

In accompanying drawings there is shown a lathe 10 that has a turret head 12 operatively mounted thereon. The turret selected for illustration is a hex-turret inasmuch as this is one of the most common forms of turrets, although it is understood that the principles of the invention are applicable to other types of turrets, and in fact, the principles of the invention are applicable to other machine tools.

The tap 14 has a shank 16 which is adapted to fit in one of the openings of the turret 12 and to be locked in place. The tap has threads17 and a cutting edge 18 constructed of a plurality of teeth with spaced openings 20 between the teeth arranged in a circle and is conventional tap structure. The cutting teeth are tapered and when one full tooth wears out a new full tooth is ground so that there will be at least the required minimum of teeth on the cutting edge.

Shank 16 has a support structure 22 attached to it on which there is a small electric motor 24 that drives pump 26 which may be of the positive displacement type, as a gear pump. Gearing 28 drivingly connects motor 24 with 2,975,441 Patented Mar. 21, 1961 gear pump 26. The inlet pipe or line 30 for the pump is connected to the pump casing and to reservoir 32 beneath the support 22. The reservoir is attached to supporting structure 22 by one or more braces 34 and has an oil inlet communicating with a sloped tray 36 that extends laterally from the reservoir 32 and beneath the tap 14. Accumulation of cutting oil from the tap is received in a tray 16 and passes into the reservoir through an opening (not shown) that registers with the sloping tray.

A discharge port of pump 26 has a pipe or line 38 connected to it and connected also to tank 40 held elevated by a part of the support structure 22. Pipe or line 42 extends from tank 40 and has a valve 44 interposed between its ends. One end of the pipe 42 is attached to tank 40 to conduct oil therefrom while the other end is attached to collar 50 on shank 16.

Collar 50 (Figure 3) has a counterbore forming an annular manifold 52 in front of the threads 54 of the collar that attach the collar onto a threaded part of shank 16. Seal 56 is disposed between the flange 58 on collar 50 and the last thread on shank 16. Gasket 60 is at the opposite end of the collar and abuts shoulder 62 at the inner extremity of threads 17. The gasket, a part of the wall of shank 16, and the walls of the counterbore constitute the annular manifold 52 within which oil is fed under pressure through pipe 42.

A plurality of longitudinal passageways 66 are formed in the side wall 68 of tap 14 between the hollow central cavity 70 and the outer surface of the tap .14. The ends of the passageways 66 open through the inntermost walls of the openings 20 in order that some oil may be fed into these openings 20 to fully flush the workpiece that is being tapped, to conduct chips away and to keep it cool and for other reasons which make the application of cutting oil desirable during machine tool cutting operations. Lateral pasages 74 communicate with passageways 66 a few threads back from the cutting edges of the tool so that the area of the tap in this region of the tool may he kept lubricated.

Cavity 70 has a passage 78 at its inner end with which lateral passage 80 is connected. The lateral passage has a pipe 82 secured in it which connects to the reservoir 32 so that oil may be returned to the reservoir through this route.

As shown in Figures 6 and 7 the fluted tap 14a may be constructed very much like tap 14. The only difference between taps 14 and 14a is in the thread pattern, the tap 14:: having flutes in the threads 17w.

What is claimed as new is as follows:

The combination of a tap comprising a shank having a threaded portion terminating in a cutting end provided with a plurality of circumferentially spaced openings in terrupting said threaded portion, said shank also having a diametrically reduced portion providing an annular shoulder at the junction thereof with said threaded portion, the threaded portion of the shank being provided with a plurality of circumferentially spaced. longitudinally extending passages having open ends in said openings and at said shoulder, a collar mounted on the reduced portion of the shank in abutment with said shoulder and provided with an annular groove constituting a manifold in communication with the open ends of said passages at said shoulder, the cutting end portion of the shank being cavity to a side of the shank, and means disposed under the threaded portion of the shank for collecting fluid discharged through said passages and recirculating the collected fluid through said means for delivering fluid to said manifold.

Newton May 4,, 1897 Condict June 21, 1910 4 Landis -1-.. Feb. 20, 1912 Oster Nov. 9, 1915 Stolle Oct. 28, 1924 Schubert Aug. 20, 1940 Mallory Feb. 10, 1942 Allison Sept; 9, 1947 Atkinson Sept. 16, 1952 FOREIGN PATENTS France ..7 Feb. 3, 1954 

